I see a couple of mentions here about ".890" bars.
I found listings for b/e bodies of .880 and .900...... Didn't see any for .890.

I don't think I'm knew there was a .900 bar, I just thought there was the 6 cyl bar(.860), v8 bar(.880), 440/hemi bar(.920).
Apparently there is also the .900 bar(383-4bbl).
Guess I'll have to check the numbers on mine to see which they are.
In theory, if they're original, they should be .900 since it's a 383-4bbl car.
I thought I measured them at something less than .900 at some point.